Arrangement for determining the internal resistance of a lambda probe

US6073083A · kind A · utility

Assignee

• Robert Bosch GmbH · DE

Inventors

• Eberhard Schnaibel · Hemmingen, DE
• Erich Junginger · Stuttgart, DE
• Lothar Raff · Waiblingen, DE

Key dates

• Filing date: Sep 5, 1997
• Grant date: Jun 6, 2000
• Expiry date: Sep 5, 2017

Classification

• Technology area (CPC F): Mechanical Engineering; Lighting; Heating
• CPC primary: F02D41/1456
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

The invention is directed to an arrangement for determining the internal resistance of a lambda probe having a positive pole and an internal resistance. A computer includes at least one computer port having a switchable state, a signal input and fixed pregiven values. A supply voltage source having a positive pole and a measurement resistor are also provided. The positive pole of the supply voltage source is connected to the positive pole of the lambda probe via the computer port and the measurement resistor. An analog/digital converter is connected forward of the signal input and the positive pole of the lambda probe is connected directly to the analog/digital converter for applying variable values to the signal input via the analog/digital converter. The computer is adapted to compute the internal resistance of the lambda probe from the variable values applied to the signal input and the fixed pregiven values. A method of determining the internal resistance of a lambda probe is also disclosed.